Linux Basics CS 302

Outline  What is Unix?  What is Linux?  Virtual Machine.

What is Unix?

 An operating system developed in the 1960s.  It is multi-user and multi-tasking operating system.  The most popular varieties of UNIX are Sun Solaris, GNU/Linux, and MacOS X.  The UNIX operating system is made up of three parts; the kernel, the shell and the programs

What is Unix (Cont.)  The Kernel : a program that manages computer resources and handles system calls.  The Shell : a command line interpreter (CLI) that acts as an interface between the user and kernel.

What is Linux?

Linux History  GNU Project:  Started at 1983 by Richard Stallman.  Goal: creating a UNIX-like free operating system.  His vision: software should be free from restrictions against copying or modification in order to make better and efficient computer programs.  By 1991 GNU created a lot of tools, but there was still no operating system.

Linux History (Cont.)  In 1991:  Linux kernel is developed by Linus Torvalds.  combining Linux kernel with the not-quite-complete GNU system resulted in a complete free operating system called Linux.  Today’s Linux distribution consists of:  Linux Kernel  GNU (GNU is Not Unix) Software  Software Package management  Others

Linux is Open Source Software  When programmers on the Internet can read, redistribute, and modify the source for a piece of software, it evolves  People improve it, people adapt it, people fix bugs. And this can happen at a speed that, compared to conventional software development.

Linux Distributions  Various organizations package the Linux kernel and system programs as Linux distributions  Such as : Ubuntu, Red Hat, and Mandriva.

Common Linux features  Multiuser:  Multiple users can log in and working on the system at the same time  Multiuser systems divide computer resources among multiple users, allowing for more efficient use of these resources.  Multitasking:  it is possible to have many programs running at the same time  Graphical User Interface (X Window System)  Hardware support  you can configure support for almost every type of hardware that can be connected to a computer  Networking connectivity:  Linux offers support for a variety of local area network boards, modems, and serial devices.

Common Linux features (Cont.)  Application support  a wide range of freeware and shareware software is available for Linux.  Most of Linux is written in the C programming language. When written in a portable style, C programs can be moved from one platform (processor or CPU-based system) to another by simply recompiling the code.

Redhat

Virtual Machine

 A virtual machine (VM) is a "completely isolated guest operating system installation within a normal host operating system“  Virtualization lets you run multiple virtual machines on a single physical machine, with each virtual machine sharing the resources of that one physical computer across multiple environments.  VMware is an example of virtual machines software